Mechanical system comprising a sensor bearing unit and associated mounting method

ABSTRACT

A mechanical system includes a sensor bearing unit and a fixed support part. The sensor bearing unit includes a bearing including a first ring and a second ring centered on an axis, an impulse ring secured to the first ring of the bearing, and a sensor device for detecting rotational parameters of the impulse ring. The sensor device has a sensor housing secured to the second ring of the bearing and a cable output that extends radially and is located circumferentially two spaced protrusions of the fixed support part.

CROSS-REFERENCE

This application claims priority to Indian patent application no.202141022136 filed on May 17, 2021, the contents of which are fullyincorporated herein by reference.

TECHNOLOGICAL FIELD

The present disclosure relates to a mechanical system comprising asensor bearing unit comprising a bearing, an impulse ring and a sensordevice.

BACKGROUND

Today, sensor bearing units are commonly used in a wide range oftechnical fields, for example in the automotive industry andaeronautics. These units provide high quality signals and transmissions,while allowing integration in simpler and more compact apparatus.

A sensor bearing unit generally comprises a bearing, an impulse ringsecured to the rotatable ring of the bearing, and a sensor unit ordevice for sensing the angular position of the impulse ring with respectto the fixed ring of the bearing.

Conventionally, the impulse ring is provided with a target holdersecured onto the rotatable inner ring and with a magnetic target securedto the target holder. The sensor device is provided with a sensorelement facing the magnetic target of the impulse ring in order todetermine, on the basis of the magnetic field variations, the angularposition of the rotatable ring.

The sensor device is provided with a sensor housing supporting thesensor element and secured to the fixed outer ring of the bearing. Tothis end, the sensor device may be further provided with a metallicsupport secured into a groove formed on the bore of the outer fixed ringand inside which is mounted the sensor housing. For more details, it ispossible for example to refer to the patent application WO 2009/004198.

During the mounting of the sensor bearing unit in the associatedapparatus, such solution requires a mechanical angular positioning ofthe sensor housing inside the metallic support, and then a plasticdeformation of this support to block rotation of the sensor housing.

SUMMARY

One aim of the present disclosure is to overcome this drawback.

The disclosure relates to a mechanical system comprising a sensorbearing unit and a fixed support part. The sensor bearing unit comprisesa bearing including a first ring and a second ring centered on an axis,an impulse ring secured to the first ring of the bearing, and a sensordevice for detecting rotational parameters of the impulse ringcomprising a sensor housing secured to the second ring of the bearingand provided with a cable output.

According to a first general feature, the cable output of the sensorhousing of the sensor device extends radially.

According to a second general feature, the cable output is locatedcircumferentially between two spaced protrusions of the fixed supportpart.

With such a design, position of the cable output of the sensor housingof the sensor device is predetermined and locked in the circumferentialdirection. The cable output of the sensor housing and the protrusions ofthe non-rotating support part form an anti-rotation means of the sensorhousing and the second ring of the bearing.

This design does not require a plastic deformation of a part of themechanical system to angularly secure the sensor housing of the sensordevice.

In one embodiment, the protrusions of the fixed support part extend atleast axially.

Preferably, a circumferential clearance is provided between eachprotrusion of the fixed support part and the cable output of the sensorhousing of the sensor device of the sensor bearing unit.

This facilitates the mounting of the cable output between the two facingprotrusions of the fixed support part.

In one embodiment, the cable output of sensor housing of the sensordevice of the sensor bearing unit protrudes radially outwards withrespect to the outer surface of the sensor housing.

The sensor device of the sensor bearing unit may further comprise atleast one sensor element supported by the sensor housing and cooperatingwith the impulse ring, and one cable engaged inside the cable output ofthe sensor housing and connected to the sensor element.

In one embodiment, the sensor element of the sensor device axially facesthe impulse ring. Alternatively, the sensor element may radially facethe impulse ring.

In one embodiment, the impulse ring is made of metal and provided withalternating teeth and apertures and the sensor element of the sensordevice is configured to sense the metal impulse ring teeth andapertures.

The sensor element may directly face the impulse ring, or indirectlycooperate with the impulse ring, i.e. with interposition of an elementaxially between the impulse ring and the sensor element.

In one embodiment, the sensor housing of the sensor device of the sensorbearing unit comprises an annular outer axial portion, and annular inneraxial portion and an annular radial portion extending between the outerand inner axial portions. The cable output protrudes radially outwardswith respect to the outer axial portion of the sensor housing.

In one embodiment, the sensor housing may be secured into a grooveformed on a cylindrical surface of the second ring of the bearing whichis located radially on the side opposite to the first ring.

With such design, the sensor housing is not secured on a cylindricalsurface of the first or second ring which radially faces the second orfirst ring, and is not located radially between the first and secondrings. Therefore, if necessary, the bearing may be provided with sealseach secured into a groove formed on a cylindrical surface of the firstor second ring which radially faces the second or first ring. The sealsmay be radially disposed between the first and second rings.

The sensor housing of the sensor device may be provided with a snappingportion engaged partly inside the groove of the second ring.

In one embodiment, the cylindrical surface of the second ring of thebearing has a stepped shape with a first cylindrical portion and with asecond cylindrical portion radially offset towards the first ring withrespect to the first cylindrical portion, the groove being axiallylocated between the first and second cylindrical portions.

With such embodiment, the snapping portion of the sensor housing of thesensor device may be radially offset towards the first ring of thebearing with respect to the first cylindrical portion of the cylindricalsurface or being flush with the first cylindrical portion.

Accordingly, the snapping portion of the sensor housing of the sensordoes not protrude radially with respect to the cylindrical surface ofthe second ring. The radial boundary dimension of the bearing isunchanged.

In a second alternative embodiment, the cylindrical surface of thesecond ring of the bearing may be provided with one single diameter.

In one embodiment, the groove is formed on the outer cylindrical surfaceof the second ring which forms the outer ring of the bearing.Alternatively, the groove may be formed on the inner cylindrical bore ofthe second ring which forms the inner ring of the bearing.

The disclosure further relates to a method for mounting a sensor bearingunit in a mechanical system as previously defined, wherein the methodcomprises at least the following step:

fastening the sensor bearing unit to the fixed support part with thecable output of the sensor housing of the sensor device fitted betweenthe two spaced protrusions of the fixed support part.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention and its advantages will be better understood bystudying the detailed description of a specific embodiment given by wayof a non-limiting example and illustrated by the appended drawings onwhich:

FIG. 1 is an axial section view of a sensor bearing unit according to anexample of the disclosure.

FIGS. 2 and 3 are detail views of FIG. 1.

FIG. 4 is a front view of the sensor bearing unit of FIG. 1.

FIG. 5 is a perspective view of an impulse ring of the sensor bearingunit of FIG. 1.

FIG. 6 is a front view of the impulse ring of FIG. 5.

FIG. 7 is an axial view of the sensor bearing unit of FIG. 1 and amounting tool.

FIG. 8 is a perspective view of the mounting tool of FIG. 7.

FIG. 9 is a partial axial section view of a mechanical system providedwith the sensor bearing unit of FIG. 1.

FIG. 10 is a partial perspective view of the mechanical system of FIG.10.

DETAILED DESCRIPTION

The sensor bearing unit 10 represented in FIG. 1 is adapted to equip amechanical system such as a motor, a brake system, a suspension systemor any rotating machine, in particular for an automotive vehicle or atwo-wheeled vehicle.

Such a mechanical system is shown partially in FIGS. 9 and 10 and isprovided with a rotating shaft 11 and a non-rotating or fixed casing 13.If the mechanical system is an electric motor, a rotor is secured to theshaft 11 and a stator is secured to the casing 13. The sensor bearingunit 10 is mounted on the shaft 11 and in the casing 13. The sensorbearing unit 10 may be received into a shield of the casing 13.Alternatively, the sensor bearing unit 10 may be received into the boreof the casing 13.

As shown in FIG. 1, the sensor bearing unit 10 comprises a bearing 12and an impulse ring 14 and a sensor device 16 mounted on the bearing.The bearing 12 is intended to be mounted on the shaft 11 (FIGS. 9 and10) of the mechanical system for tracking the rotation of the shaft.

The bearing 12 comprises a first ring 18 and a second ring 20. In theillustrated example, the first ring 18 is the inner ring whereas thesecond ring 20 is the outer ring. The inner and outer rings 18, 20 areconcentric and extend axially along the bearing rotation axis X-X′ whichruns in an axial direction. The outer ring 20 radially surrounds theinner ring 18. The inner and outer rings 18, 20 are made of steel.

As will be described later, the impulse ring 14 is secured to the innerring 18 and the sensor device 16 is secured to the outer ring 20.

In the illustrated example, the bearing 12 also comprises a row ofrolling elements 22, which are provided here in the form of balls,interposed between raceways (not referenced) formed on the inner andouter rings 18, 20.

The bearing 10 also comprises a cage 24 for maintaining the regularcircumferential spacing of the rolling elements 20. The bearing 10further comprises seals 26, 28 radially disposed between the inner andouter rings 18, 20 to define a closed space inside which the rollingelements 22 are arranged.

The inner ring 18 of the bearing is mounted on the outer surface of theshaft 11 (FIGS. 9 and 10) of the mechanical system. The inner ring 18 isintended to rotate while the outer ring 20 is intended to be fixed. Theouter ring 20 is mounted into a bore of the fixed casing 13 (FIGS. 9 and10) of the mechanical system.

The outer ring 20 is provided with a cylindrical inner surface or bore20 a and with an outer cylindrical surface 20 b which is radiallyopposite the bore 20 a. The outer surface 20 b is located radially onthe side opposite the inner ring 18. The bore 20 a radially faces theinner ring 18. In the illustrated example, a toroidal circular racewayfor the rolling elements 22 is formed from the bore 20 a, the racewaybeing directed radially inwards. Two grooves (not referenced) are alsoformed on the bore 20 a into which are secured the seals 26, 28.

The outer ring 20 is also provided with two opposite radial lateralfaces 20 c, 20 d which axially delimit the bore 20 a and the outersurface 20 b of the ring.

As shown more clearly in FIG. 2, a groove 30 is formed on the outersurface 20 b of the outer ring. The groove 30 is oriented radiallyoutwards, i.e. radially on the side opposite the inner ring. The groove30 extends radially inwards from the outer surface 20 b of the outerring. In the illustrated example, the groove 30 has an annular form.

The groove 30 is axially delimited by two side walls 30 a, 30 b. Theside walls 30 a, 30 b axially face each other. The side walls 30 a, 30 bare axially spaced apart from each other. The groove 30 also comprises abottom 30 c connected to the side walls 30 a, 30 b. The outer surface 20b of the outer ring and the bottom 30 c of the groove are radiallyoffset. The bottom 30 c is radially offset inward with regard to theouter surface 20 b. The side walls 30 a, 30 b of the groove extendradially. The bottom 30 c extends axially. The groove 30 has a U-shapedcross-section.

In the illustrated example, the outer surface 20 b of the outer ring hasa stepped shape. The outer surface 20 b is provided with a firstcylindrical portion 20 b ₁ and with a second cylindrical portion 20 b ₂which is radially offset inwards, i.e. towards the inner ring, withrespect to the first cylindrical portion 20 b ₁. The groove 30 isaxially interposed between the first and second cylindrical portions 20b ₁, 20 b ₂.

The side wall 30 b of the groove axially delimits the first cylindricalportion 20 b 1. More precisely, the first cylindrical portion 20 b 1 isaxially delimited by the lateral face 20 d (FIG. 1) and the side wall 30b. The side wall 30 a of the groove axially delimits the secondcylindrical portion 20 b ₂. More precisely, the second cylindricalportion 20 b 2 is axially delimited by the lateral face 20 c and theside wall 30 a.

Referring once again to FIG. 1, similarly to the outer ring 20, theinner ring 18 is provided with a cylindrical inner surface or bore 18 aand with an outer cylindrical surface 18 b which is radially oppositethe bore 18 a. The outer surface 18 b radially faces the outer ring 20.The bore 18 a is located radially on the side opposite to the outer ring20. In the illustrated example, a toroidal circular raceway for therolling elements 22 is formed from the outer surface 18 b, the racewaybeing directed radially outwards.

The inner ring 18 is also provided with two opposite radial lateralfaces 18 c, 18 d which axially delimit the bore 18 a and the outersurface 18 b of the ring.

As shown more clearly in FIG. 3, a groove 32 is formed on the bore 18 aof the inner ring. The groove 32 is oriented radially inwards, i.e.radially on the side opposite to the outer ring. The groove 32 extendsradially outwards from the bore 18 a of the inner ring. In theillustrated example, the groove 32 has an annular form.

The groove 32 is axially delimited by two side walls 32 a, 32 b. Theside walls 32 a, 32 b axially face each other. The side walls 32 a, 32 bare axially spaced apart from each other. The groove 32 also comprises abottom 32 c connected to the side walls 32 a, 32 b. The bore 18 a of theinner ring and the bottom 32 c of the groove are radially offset. Thebottom 32 c is radially offset outward with regard to the bore 18 a. Inthe illustrated example, the side walls 32 a, 32 b of the groove extendradially. Alternatively, the side wall 32 b may extend obliquely. Thebottom 32 c extends axially. The groove 32 has here a U-shapedcross-section.

In the illustrated example, the bore 18 a of the inner ring has astepped shape. The bore 18 a is provided with a first cylindricalportion 18 a ₁ and with a second cylindrical portion 18 a 2 which isradially offset outwards, i.e. towards the outer ring, with respect tothe first cylindrical portion 18 a ₁. The groove 32 is axiallyinterposed between the first and second cylindrical portions 18 a ₁, 18a ₂.

The side wall 32 b of the groove axially delimits the first cylindricalportion 18 a ₁. More precisely, the first cylindrical portion 18 a ₁ isaxially delimited by the lateral face 18 d (FIG. 1) and the side wall 32b. The side wall 32 a of the groove axially delimits the secondcylindrical portion 18 a ₂. More precisely, the second cylindricalportion 18 a ₂ is axially delimited by the lateral face 18 c and theside wall 32 a.

Referring once again to FIG. 1 and as previously indicated, the sensordevice 16 is secured to the outer ring 20. The sensor device comprises asensor body or housing 34 and sensor elements 36 (only one being visiblein FIG. 1) supported by the sensor housing 34. The sensor device 16 alsocomprises a printed circuit board 38 secured to the sensor housing 34and supporting the sensor elements 36. In the illustrated example, thesensor device 16 also comprises a connecting cable 40 for transmittingsensing data.

The sensor housing 34 has an annular form. The sensor housing 34 issecured into the groove 30 formed on the outer surface 20 b of the outerring. The sensor housing 34 is provided with an annular hook 42 engagedinside the groove 30 to axially retain the sensor housing 34 relative tothe outer ring. The hook 42 extends radially. The hook 42 axially abutsagainst the radial side wall 30 a of the groove. In the illustratedexample, the hook 42 also radially abuts against the bottom 30 c of thegroove. Alternatively, a slight radial gap may remain between the hook42 and the bottom 30 c.

In the illustrated example, the sensor housing 34 is provided with anannular hook 42. Alternatively, the sensor housing 34 may be providedwith a plurality of hooks 42 spaced apart in the circumferentialdirection, preferably regularly, and each engaged inside the groove 30of the outer ring.

The sensor housing 34 comprises an annular outer axial portion 44provided with the hook 42, an annular inner axial portion 46 and anannular radial portion 48 extending between the outer and inner axialportions. The outer and inner axial portions 44, 48 are concentric andcoaxial with the axis X-X′.

The outer axial portion 44 of the sensor housing radially surrounds theinner portion 46. The outer axial portion 44 extends axially from theradial portion 48 towards the bearing 12. The outer axial portion 44extends axially from a large-diameter edge of the radial portion 48.

A part 44 a of the outer axial portion 44 radially surrounds the outersurface 20 b of the outer ring. The hook 42 extends radially inwardsfrom this part 44 a of the outer axial portion 44. The part 44 a of theouter portion 44 radially surrounding the outer surface 20 b of theouter ring and the hook 42 form together a snapping portion of thesensor housing 34. The part 44 a of the outer axial portion radiallycomes into contact with the outer surface 20 b of the outer ring. Thepart 44 a of the outer axial portion radially comes into contact withthe second cylindrical portion 20 b ₂ of the outer surface. The free endof the outer axial portion 44, namely the free end of the part 44 a,axially abuts against the side wall 30 b of the groove of the outerring. The hook 42 is provided at the free end of the outer axial portion44.

The part 44 a of the outer axial portion is radially offset inwards,towards the inner ring 18, with respect to the first cylindrical portion20 b ₁ of the outer surface of the outer ring. In the illustratedexample, the outer axial portion 44 is entirely radially offset inwardswith respect to the first cylindrical portion 20 b ₁.

The outer axial portion 44 of the sensor housing axially protrudestowards the bearing 12 with regard to the inner axial portion 46. Theinner axial portion 46 defines the bore of the sensor housing 34. Theinner axial portion 46 extends axially from the radial portion 48towards the bearing 12. The inner axial portion 46 extends axially froma small-diameter edge of the radial portion 48. The inner axial portion46 remains axially spaced apart from the bearing 12 and the impulse ring14.

The sensor housing 34 defines an annular space 50 axially orientedtowards the bearing 12. The space 50 is radially delimited by the outerand inner axial portions 44, 46. The space 50 is axially delimited bythe radial portion 48.

In the illustrated example, the sensor housing 34 also comprises a cableoutput 52 which extends radially and inside which is engaged the cable40. The cable output 52 forms a protruding portion extending radiallyoutwards from the outer surface of the sensor housing 34. The cableoutput 52 protrudes radially outwards from the outer axial portion 44 ofthe sensor housing. Only the cable output 52 radially protrudes outwardswith respect to the outer surface of the sensor housing 34.

In the illustrated example, the cable output 52 has a tubular form.Alternatively, the cable output 52 may have other shapes, for example arectangular parallelepiped form. The cable 40 protrudes outwards fromthe cable output 52. The cable 40 is secured into the cable output 52 byany appropriate means, for example by press-fitting or gluing. The cable40 comprises several electrical wires (not shown) connected to theprinted circuit board 38. The cable 40 is connected to the sensorelements 36 by the printed circuit board 38.

The sensor body 34 is made in one part. The sensor body 30 is made of asynthetic material. For example, the sensor body 34 may be made of Nylon66 (PA 6.6) or Polybutylene terephthalate (PBT). Alternatively, thesensor body 34 can also be made from other materials, for example steel.

The printed circuit board 38 is secured to the sensor housing 34. Theprinted circuit board 38 is housed inside the space 50 defined by thesensor housing 34. In the illustrated example, the printed circuit board38 is secured to the inner axial portion 46 of the sensor body.Alternatively, the printed circuit board 38 may be secured to the outeraxial portion 44 of the sensor body.

The sensor elements 36 are supported by the printed circuit board 38which is itself supported by the sensor housing 34. As will be describedlater, the sensor elements 36 are mounted on the printed circuit board38 axially on the side of the impulse ring 14.

As previously mentioned, the impulse ring 14 is secured to the innerring 18. The impulse ring 14 is secured into the bore 18 a of the innerring. The impulse ring 14 is secured into the groove 32 formed on thebore 18 a. In the disclosed example, the impulse ring 14 is made in onepart. The impulse ring 14 is made of metal.

As shown in FIGS. 1, 5 and 6, the impulse ring 14 comprises an annularradial portion 54, and a plurality of inner axial lugs 56 extendingaxially from the radial portion 54. The lugs 56 extend axially inwardsthe radial portion 54. The lugs 56 extend axially a small-diameter edgeof the radial portion 54. The lugs 56 are spaced apart in thecircumferential direction, here regularly. The lugs 56 are hereidentical one to another. In the illustrated example, four lugs 56 areprovided. Alternatively, a different number of lugs 56 may be foreseen,for example at least two lugs. For example, each lug 56 may extend overan angular sector comprised between 35° and 55°, and preferably be equalto 45°.

In the illustrated example, the impulse ring 14 is axially mountedagainst the lateral face 18 c of the inner ring. The radial portion 54of the impulse ring axially abuts the lateral face 18 c. The lugs 56 aremounted into the bore 18 a of the inner ring. The lugs 56 radially comeinto contact with the bore 18 a. The lugs 56 radially come into contactwith the second cylindrical portion 18 a 2 of the bore.

Each lug 56 is provided with a hook 58 extending radially and engagedinside the groove 32 to axially retain the impulse ring 14 relative tothe inner ring 18. Each hook 58 extends radially outwards from theassociated lug 56. Each hook 58 axially abuts against the radial sidewall 32 a of the groove. Each hook 58 is provided at the free end of theassociated lug 56. Each hook 58 and the associated lug 56 have anL-shape in cross-section. The lugs 56 and the hooks 58 form together asnapping portion of the impulse ring 14.

As previously mentioned, in the illustrated example, the impulse ring 14is provided with a plurality of axial lugs 56. Alternatively, theimpulse ring 14 may be provided with an annular axial portion extendingaxially from the radial portion 54, and with the hooks 58 or with anannular hook engaged inside the groove 32 of the inner ring. In suchcase, the annular axial portion and the hooks 58, or the annular hook,form together the snapping portion of the impulse ring 14.

In the illustrated example, the impulse ring 14 is provided with aplurality of through-openings 60 formed on the radial portion 54. Theopenings 60 extend through the axial thickness of the radial portion 54.The openings 60 are spaced apart in the circumferential direction, hereregularly. The openings 60 are here identical one to another. In theillustrated example, four openings 60 are provided. Alternatively, adifferent number of openings 60 may be foreseen, for example only oneopening, or at least two openings 60. For example, each opening 60 mayextend over an angular sector of from 35° to 55°, and preferably beequal to 45°. In the illustrated example, each through-opening 60 iscircumferentially disposed between two successive lugs 56 while beingradially offset outwards. Each through-opening 60 opens radiallyinwards.

Each through-opening 60 is formed on the radial portion 54 such that apart of the lateral face 18 c of the inner ring is axially accessiblefrom the outside through the opening 60. In other words, each opening 60of the radial portion 54 leaves exposed a part of the lateral face 18 cof the inner ring.

Each through-opening 60 is formed on the radial portion 54 of theimpulse ring to be radially located between the bore 18 a and the outersurface 18 b of the inner ring. Each through-opening 60 is radiallyoffset outwards with respect to the bore 18 a and radially offsetinwards with respect to the outer surface 18 b. The inner diameter ofeach through-opening 60 is larger than the diameter of the bore 18 a,and its outer diameter is smaller than the diameter the outer surface 18b.

The impulse ring 14 is also provided with a plurality of teeth 62 at itsperiphery. The teeth 62 are regularly spaced apart in thecircumferential direction. A recess or aperture 64 is provided betweeneach pair of successive teeth 62. Hence, the impulse ring 14 is providedwith alternating teeth 62 and apertures 64.

As previously mentioned, each sensor element 36 is mounted on theprinted circuit board 38 axially on the side of the impulse ring 14.Each sensor element 36 axially faces the impulse ring 14. The sensorelements 36 are disposed on the same diameter on the printed circuitboard 38. Each sensor element 36 axially faces one of the teeth 62 orapertures 64 of the impulse ring. The sensor elements 36 are regularlyspaced apart in the circumferential direction. For example, the sensordevice 16 may comprise three sensor elements 36. Alternatively, adifferent number of sensor elements 36 may be foreseen, for example oneor two sensor elements 36 or at least four sensor elements 36.

Preferably, the sensor elements 36 use induction technology. Each sensorelement 36 may include an inductive switch sensor such as a sensingcoil. The switch of each sensor element 36 is triggered by the metalimpulse ring 14. The teeth 62 and apertures 64 of the impulse ring areused as differential inductance field references.

As an alternative, the impulse ring 14 and the sensors element 36 mayuse any other suitable technology instead of induction technology. Forexample, optical technology or magnetic technology may be implemented.In case of magnetic technology, the impulse ring 14 may includealternating North and South poles and the sensor elements 36 may includeHall-effect sensors.

As previously mentioned, the bearing 12 is intended to be mounted insidea non-rotating member such as the casing 13 (FIGS. 9 and 10) of theassociated mechanical system. To this end, a mounting tool 70 as shownin FIGS. 7 and 8 may be used.

The tool 70 comprises an annular gripping portion 72 and a plurality ofaxial teeth 74 extending axially at one end of the gripping portion 72.The teeth 74 are spaced apart in the circumferential direction. Here,the teeth 74 are identical one to another. The number of teeth 74 of thetool is equal to the number of through-openings 60 of the impulse ring.The angular dimension of each tooth 74 is smaller than the one of thethrough-openings 60. Each tooth 74 is configured to be engaged into oneof the through-openings 60 of the impulse ring 14 without contact withthe impulse ring 14.

The assembly of the sensor bearing unit 10 inside the casing of themechanical system is done with the tool 70.

Firstly, the tool 70 is positioned such that each tooth 74 extendsthrough one of the openings 60 of the impulse ring and axially come intocontact with the lateral face 18 c of the inner ring of the bearing. Thethrough-openings 60 of the impulse ring allow the passage of the teeth74 of the tool to axially abut directly on the lateral face 18 c asshown in FIG. 7.

The tool 70 is partly located inside the bore of the sensor housing 34of the sensor bearing unit 10. The axial contact between the teeth 74 ofthe tool and the lateral face 18 c of the inner ring is the only contactbetween the tool 70 and the sensor bearing unit 10. There is no contactbetween the tool 70 and the impulse ring 14, or between the tool and thesensor housing 34.

Secondly, an axial force is exerted directly onto the lateral face 18 cof the inner ring of the bearing with the aid of the tool 70 in order tomount into the casing the outer ring 20 of the bearing. Preferably, theouter ring 20 is press-fitted into the casing. The through-openings 60of the impulse ring enable the tool 70 to axially push directly on theinner ring 18 of the bearing during the installation of the sensorbearing unit 10 into the casing.

Once the assembly of the sensor bearing unit 10 inside the casing 13 ofthe mechanical system is achieved, the shaft 11 is mounted inside thebore of the inner ring 18 of the bearing.

In an alternative embodiment, it could be possible to mount the bearing12 of the sensor bearing unit onto the shaft 11 of the mechanicalsystem, and then to introduce the bearing 12 inside the casing 13. Inthis case, it is possible to not foresee the through-openings 60 of theimpulse ring.

As shown in FIGS. 9 and 10, in the mounted position of the bearing 12inside the fixed casing 13, the sensor housing 34 of the sensor deviceaxially protrudes outwards with respect to the casing. The sensorhousing 34 axially protrudes outwards with respect to a frontal face 13a of the casing. The cable output 52 of the sensor housing is axiallylocated outside of the casing 13.

The bearing 12 is mounted inside the fixed casing 13 such that the cableoutput 52 of the sensor housing 34 is circumferentially located betweentwo axial protrusions 82 of the casing. The protrusions 82 axiallyprotrude with respect to the frontal face 13 a of the casing. Theprotrusions 82 are spaced apart from each other in the circumferentialdirection. The protrusions 82 face each other. The protrusions 82 formaxial lugs.

The circumferential spacing between the protrusions 82 of the casing issized according to the dimension of the cable output 52 of the sensorhousing 34. For example, a circumferential clearance may be providedbetween each protrusion 82 and the cable output 52. Such clearance maybe for example equal to 1 mm or 2 mm.

Since the cable output 52 of the sensor device 16 is fitted between theprotrusions 82 of the non-rotating casing 13, this leads to an absolutepositioning of the sensor housing 34 supporting the sensor elements 36.The cable output 52 of the sensor device 16 and the protrusions 82 ofthe casing also prevent a rotation of the sensor device 16 and the outerring 20 of the bearing around the bearing axis X-X′.

This corresponds to the initial positioning of the sensor device. Thespeed, position and direction are detected with respect to this initialposition.

As previously mentioned, in this illustrated example, the first ring ofthe rolling bearing is the inner rotatable ring whereas the second ringis the outer fixed ring. As an alternative, it could be possible toprovide a reversed arrangement with the first ring forming the outerrotatable ring and the second ring forming the inner fixed ring. In thiscase, the impulse ring 14 is secured to the outer ring, and the sensordevice 16 may be secured to the inner ring.

In the illustrated examples, the sensor bearing unit is provided with arolling bearing comprising one row of rolling elements. Alternatively,the rolling bearing may comprise at least two rows of rolling elements.In the illustrated examples, the rolling elements are balls.Alternatively, the rolling bearing may comprise other types of rollingelements, for example rollers. In another variant, the rolling bearingmay also be provided with a sliding bearing having no rolling elements.

Representative, non-limiting examples of the present invention weredescribed above in detail with reference to the attached drawings. Thisdetailed description is merely intended to teach a person of skill inthe art further details for practicing preferred aspects of the presentteachings and is not intended to limit the scope of the invention.Furthermore, each of the additional features and teachings disclosedabove may be utilized separately or in conjunction with other featuresand teachings to provide improved sensor bearing units.

Moreover, combinations of features and steps disclosed in the abovedetailed description may not be necessary to practice the invention inthe broadest sense, and are instead taught merely to particularlydescribe representative examples of the invention. Furthermore, variousfeatures of the above-described representative examples, as well as thevarious independent and dependent claims below, may be combined in waysthat are not specifically and explicitly enumerated in order to provideadditional useful embodiments of the present teachings.

All features disclosed in the description and/or the claims are intendedto be disclosed separately and independently from each other for thepurpose of original written disclosure, as well as for the purpose ofrestricting the claimed subject matter, independent of the compositionsof the features in the embodiments and/or the claims. In addition, allvalue ranges or indications of groups of entities are intended todisclose every possible intermediate value or intermediate entity forthe purpose of original written disclosure, as well as for the purposeof restricting the claimed subject matter.

What is claimed is:
 1. A mechanical system comprising a sensor bearingunit and a fixed support part, the sensor bearing unit comprising: abearing including a first ring and a second ring centered on an axis, animpulse ring secured to the first ring of the bearing, and a sensordevice for detecting rotational parameters of the impulse ring, thesensor device including a sensor housing secured to the second ring ofthe bearing and having a cable output, wherein the cable output extendsradially and is located circumferentially two spaced protrusions of thefixed support part.
 2. The mechanical system according to claim 1,wherein the protrusions extend at least axially from the fixed supportpart.
 3. The mechanical system according to claim 1, wherein acircumferential space tween the two spaced protrusions is greater than awidth of the cable output in the circumferential direction.
 4. Themechanical system according to claim 1, wherein the cable outputprotrudes radially outwards from the sensor housing.
 5. The mechanicalsystem according to claim 1, wherein the sensor device furthercomprises: at least one sensor element supported by the sensor housingand facing the impulse ring, and a cable inside the cable output andoperatively connected to the sensor element.
 6. The mechanical systemaccording to claim 5, wherein the impulse ring is made of metal andincludes alternating teeth and apertures, and wherein the sensor elementis configured to sense the metal impulse ring teeth and apertures. 7.The mechanical system according to claim 1, wherein the sensor housingcomprises an annular axially extending outer portion, an annular axiallyextending inner portion and an annular radially extending portionextending between the outer portion and the inner portion.
 8. Themechanical system according to claim 7, wherein the cable outputprotrudes radially outwards from the sensor housing.
 9. The mechanicalsystem according to claim 1, wherein the sensor housing is secured in agroove formed on a cylindrical surface of the second ring of thebearing, the groove being located radially on a side of the second ringopposite to the first ring.
 10. The mechanical system according to claim1, wherein the first ring is a bearing inner ring and the second ring isa bearing outer ring.
 11. The mechanical system according to claim 10,including an electrical cable extending through the cable output. 12.The mechanical system according to claim 11, wherein the cable output isintegrally formed with the sensor housing.
 13. The mechanical systemaccording to claim 12, wherein the sensor housing is secured in a grooveformed on a cylindrical surface of the bearing outer ring, the groovebeing located radially on a radially outer side of the bearing outerring.
 14. A method comprising: providing a fixed support part having anopening and two circumferentially spaced protrusions adjacent to theopening; providing a sensor bearing unit including a bearing having afirst ring and a second ring centered on an axis, an impulse ringsecured to the first ring of the bearing, and a sensor device fordetecting rotational parameters of the impulse ring, the sensor deviceincluding a sensor housing secured to the second ring of the bearing andhaving a radially extending cable output, and inserting the sensorbearing unit into the opening with the cable output located between thetwo circumferentially spaced protrusions.
 15. The method according toclaim 14, including an electrical cable extending through the cableoutput, wherein the second ring is a bearing outer ring.